It takes extremely strong arms to mount and dismount printer spindles to printing machines, especially since the spindles are to be mounted within the printing machines in out-of-the-way locations under the machine frame. Persons intending to mount or remove a spindle, be it empty or full, must access the area within the printing machine by bending and reaching under the machine frame.
Even empty spindles are heavy, and the awkward location of the spindle in a printing machine increases the effort required to remove it safely from its mounted position within the machine. For safety, at least two relatively strong individuals are required to remove and mount spindles. However, time constraints often dictate that the closest person available perform the job and the result can quite easily be back strain or injury.
Lifting carts have been made available for transporting other types of spools. One example is illustrated in U.S. Pat. No. 3,279,753 granted to Ventriglio et al. The disclosed spool carrier is used primarily for cable spools and is not directed to the problem of mounting and dismounting spools from printing presses. The cart includes a wheel supported frame with a pivoted lifting frame. The lifting frame includes a semi-circular cut-out at a forward end, and a handle at an opposite end. The center shaft of a spindle is received in the cut-out and is lifted by pushing down on the handle. A stop limits pivotal movement of the handle so the cut-out area never becomes elevated above the pivot axis for the lift frame. The entire arrangement is not intended to shift the spool back and forth on the frame to and from a location between the wheels, but simply to lift the spool to facilitate stripping of cable therefrom. Consequently, such a device could not be adequately used for mounting and dismounting paper spindles from printing presses.
Other lifting devices have also been developed for hoisting and transporting spools. U.S. Pat. No. 764,344 to Buckelew for example shows a lift truck for paper rolls and the like that does allow some lateral shift of the spool, but includes a frame and front wheel structure that projects forwardly of the lifting frame and, as such would not permit adequate access to printing machines. While the lift frame provides a latch mechanism to hold the frame in the lifted position, the entire weight of the spool is always born directly on the lift frame at a position upwardly adjacent to the front wheels of the truck, and forward of the pivot axis.
Other spool lift devices have similar structural design obstacles that prevent their use for the intended purpose of the present invention, to enable a single person to safely and easily mount and dismount and transport printing paper spools to and from printing presses.
The present invention thus has for an objective, a solution to the above problems by provision of a lifting and transporting cart with specific structural features that enable safe and easy use unique to the printing industry in removing, mounting and transporting printing paper rolls to and from printing presses.